National storm chasers are "fly by night" workers, here today, gone tomorrow. Who will you call if you have a problem or question of any kind?
Out-of-town storm chasers have no community roots and often have limited to no experience with the area laws and building codes. When they disappear, who is held accountable? You.
Storm chasers often have low standards on material quality. They are here to make the most amount of money in the shortest amount of time, at your expense.
Storm chasing companies tend to hire as many people as they can to cover multiple neighborhoods at a time to see what sticks. These people are very personable and very scripted door-to-door salesmen. They are highly trained to lock you in as a customer.
Storm chasers sometimes do not offer warranties. If they do, will you be able to reach them if you have a problem? Do not be fooled by what they promise in their sales pitch.
Storm chasers often have a large turnover of traveling crews that are on a tight timeline. This causes inconsistent quality of work. You may get a crew that just came into town, or newly formed, or you may get an established crew- it's really hit or miss. Do you want them to practice on your roof?
TIP: When choosing a roofing contractor, always be sure you are dealing with the man whose name is on the license.